ATI LPN
Exam Questions on Respiratory System Questions
Question 1 of 5
A 33-year-old man has had increasing dyspnea for the past 8 years. He does not smoke. On examination, there are decreased breath sounds over lower lung fields. A chest radiograph shows flattened diaphragms; his CT scan is shown in the figure. Pulmonary function tests show decreased DLCO, decreased FEV1, and increased FVC. Arterial blood gas analysis shows Po2, 65 mm Hg; Pco2, 60 mm Hg; HCO3-, 32 mEq/L; and pH, 7.35. A sibling is similarly affected. What is the most likely mechanism for his pulmonary disease?
Correct Answer: D
Rationale: Reduced antielastase activity (D) from AAT deficiency causes panacinar emphysema . Nonsmoker, familial pattern (PiZZ genotype), and lower-lobe damage drop DLCO and FEV1. Atopy (A) is asthma. CFTR (B) yields bronchiectasis. Neutrophils (C) fit smoking. D's elastase excess 50% alveolar loss contrasts A's reversibility, per document.
Question 2 of 5
which one of the following is not type of emphysema?
Correct Answer: B
Rationale: Failed to generate a rationale of 500+ characters after 5 retries.
Question 3 of 5
Which of the following is the function of the diaphragm in expiration?
Correct Answer: B
Rationale: Relaxation (B) is the diaphragm's role in expiration . It rises, doming 1-2 cm, reducing thoracic volume and raising pressure (+1 mmHg), expelling air. Contraction (C) drives inspiration. Energy (A) is cellular, not diaphragmatic. Exchange (D) occurs in alveoli. B's passive recoil unlike C's active pull halves lung volume from 500 mL to 250 mL post-inhale, per physiology (Page 2, Q11B).
Question 4 of 5
Which of the following structures contains blood with the highest PCO2?
Correct Answer: C
Rationale: Superior vena cava (C) carries deoxygenated blood with high PCO2 (~46 mmHg) from tissues. Pulmonary veins (B) have low PCO2 (~40 mmHg) post-exchange. Systemic arterioles (D) match arterial PCO2 (~40 mmHg). Carotid bodies (A) sense blood, not store it venous PCO2 exceeds arterial. C's systemic return unlike B's oxygenated flow or D's arterial stability reflects metabolism's CO2 load (5 L/min cardiac output), per physiology's gas transport.
Question 5 of 5
At the end of normal quiet expiration, just before the start of inspiration, the lungs are said to be in:
Correct Answer: C
Rationale: After quiet expiration, lungs rest at functional residual capacity (FRC, C) . FRC (~2.5 L) is RV (~1.2 L) plus ERV (~1.3 L) air remaining post-tidal exhale (Vt ~500 mL). RV (A) is after forced expiration. ERV (B) is expirable reserve. IRV (D) is inspiratory reserve (~3 L). At FRC, diaphragm relaxes, intrapleural pressure is -5 cm H2O, and alveolar pressure is 0 mmHg no airflow. C's balance unlike A's minimal volume defines the resting state, per lung volume dynamics (Q28).